1. Field of the Invention
The invention relates to a fuel supply system.
2. Description of Related Art
A structure is known that uses a hydrogen tank filled with compressed hydrogen to supply hydrogen gas to a fuel cell that generates energy using hydrogen gas as a fuel gas. When fuel gas is removed from this kind of a high pressure gas tank, fuel gas adiabatically expands in the tank, causing the temperature inside the tank to drop. If the temperature of the fuel gas removed from the tank is too low, it is necessary to take low temperature countermeasures at members that are arranged downstream of the tank, for example. One such measure to inhibit such a drop in the temperature inside the tank is described in Japanese Patent Application Publication No. 2002-181295 (JP-A-2002-181295), that describes a structure that makes the temperature uniform by arranging a heat-transfer member inside the tank.
However, the drop in temperature of the fuel gas due to the fuel gas adiabatically expanding inside the tank quickly progresses near the tank inside wall when fuel gas is removed from the tank. Therefore, even if a heat-transfer member is arranged inside the tank, there may be times when it is not possible to sufficiently suppress a drop in temperature of the fuel gas that is removed from the tank. Also, a structure in which a heat-transfer member is arranged inside the tank may difficult to employ because it makes the tank structure complex, reduces the amount of gas that can be filled, or increases in the tank weight.